Design of Psk Based Trusted Dtls for Smart Sensor Nodes

Background: RSA based key exchange is a heavy and time-consuming process, as it involves numerous message exchange between a client and the server. The pre-shared key (PSK) based handshake process attempts to reduce the messages during the key exchange between a client and the server. Method: This paper extends the TEE enabled dtls handshake design based on RSA to the TEE enabled pre-shared key based handshake. A dtls client and the server installs the pre-shared key in advance so that the message exchanges can be reduced during session key generation. Result: In this article, the authors have significantly reduced this penalty by fine-tuning of the tdtls algorithm for psk based handshake. On average, this gain is over 2 ms (50% - from 3.5 ms to 1.5 ms) across various cipher-suites. Conclusion: The tdtls approach increases the security of the session key and its intermediate keying materials, which is a huge gain as compared to minor handshake time increase. The algorithm ensures end-to-end security to the PSK based session key as well as its keying materials between a dtls client and a server.